The Chemical--What It Is and Why It Is Used
Major school districts, including those in New York City, Los Angeles, San Francisco and Sacramento, have quit serving apples and apple products to students because of fear over apples treated with daminozide, a growth-regulating chemical marketed mainly under the name Alar.
Meanwhile, there is confusion over exactly what the chemical is, how and why it is used and what its health effects are. Here is some basic information on the chemical.
Q: What is Alar?
A: Alar is the trade name for the compound daminozide, a plant growth regulator made by Uniroyal Chemical Co. of Middlebury, Conn., a subsidiary of Avery Inc. of New York. The company’s daminozide factory is in Louisiana. Alar’s chemical name is dutanoic acid mono(2,2-dimethylhydrazine). Uniroyal introduced daminozide in 1963 to control unwanted vegetative growth in ornamental plants. In 1968, the chemical was registered with the federal government for use on apple trees.
Q: For what is it used?
A: Daminozide, which is packaged under several brand names, is used both on food crops, such as apples, and non-food crops, such as flowers. By far, its most common application has been on apples, where it prevents the fruit from dropping or being blown off trees before it ripens. It also brings out the fruit’s color and for this reason is used mainly on red varieties. It retards growth of new branches, which block sunlight. The chemical has specific benefits for some apple species, such as promoting consistent year-to-year harvests of Red Delicious and Golden Delicious apples instead of the boom-and-bust cycle normally associated with those varieties.
It has seen very limited use on Concord grapes, cherries, peaches, nectarines, pears and peanuts.
Q: What problems are associated with it?
A: Cancer has been induced in laboratory animals exposed to high levels of daminozide for long periods. In those studies, cancers have been found in several organs, including blood vessels, liver, pancreas and uterus.
Q: How dangerous is it?
A: Long-term exposure probably increases the risk of cancer, especially if one eats a lot of apple products, although there is no consensus among test data as to the level of risk. The Environmental Protection Agency said last month that it intends to remove daminozide from the market, but said it is not dangerous enough to warrant an immediate ban; instead, the agency began an 18-month rule-review process to determine when the chemical should be banned.
The EPA said in February that recent studies confirm “an inescapable and direct correlation” between daminozide and cancer in mice, but the tests found no link between the chemical and cancer in rats. A different study in 1978 by the National Cancer Institute found the opposite to be true. Other tests found daminozide to cause cancer in mice and hamsters. Air Force studies found it to produce tumors in rats, but not in hamsters or dogs. The manufacturer points out that there is no epidemiological data indicating that either daminozide or UDMH causes cancer in humans.
In the immediate short term, test data submitted by the manufacturer to the EPA indicates that daminozide is not acutely toxic--that is, it is unlikely anyone would be able to eat enough daminozide to be poisoned by it.
Q: How much of the domestic apple crop is treated with Alar?
A: The manufacturer estimates that in 1985 Alar was applied to 40% to 50% of the fresh apple crop and about 25% of the apples for juice, apple sauce, pie fillings and other uses. Because of growing public concern over Alar residue, the manufacturer estimates that Alar is applied to only about 5% of all apples today. The apple varieties most commonly treated with Alar are MacIntosh, Red Delicious, Golden Delicious, Jonathan and Stayman. On the other hand, Granny Smith, Pippin and other green apples usually are not treated with Alar. Apples grown in California also are not treated with Alar, state regulatory officials say.
Q: Can daminozide residue be washed off?
A: No. It is designed to permeate the peel and flesh of fruit, changing the way in which they develop, making the color of the peels more vivid and the texture of the flesh more firm. Thus, daminozide residue persists in fruit even after washing and peeling. It can be transformed by cooking and processing into an even more dangerous metabolite, or breakdown product, known as UDMH. That chemical, unsymmetrical dymethyl hydrazine, is a rocket fuel and suspected carcinogen.
Q: How is it applied?
A: Powdered daminozide, which resembles flour, is mixed with water and sprayed on tree foliage after bloom but at least 70 days before harvest.
Q: Is it a threat to drinking water?
A: Company studies indicate daminozide does not linger in the environment and contaminate drinking water supplies, as some other agricultural chemicals have done.
